This ancient story has long been forgotten by most that inhabit Konohagakure.
Many years ago, before the Legendary Sannin earned their name fighting Hanzo of the Salamander, when they were simply a team of strong shinobi, one of them came upon a small child in the forest of Fire Country.
Orochimaru brought the girl back to the village where she was raised in the orphanage to become a kunoichi.
By the time the girl was six, she was able to graduate from the academy due to her skill in using both ninjutsu and iryo ninjutsu. At this time, as a student of the Hokage, Orochimaru was tasked to become her teacher.
The Hokage had seen how his student was starting down a dark path and hoped to keep him from it by introducing him to the innocence of the young girl.
And for a while, he succeeded.
But there were other powers at work within the Leaf Village, darker, more merciless powers. And Danzo wanted Orochimaru's knowledge and skill for himself.
So he planted false intel that would get the girl killed and soon Orochimaru was lost once more.
With nothing holding him back, Orochimaru descended down a path of madness, eager to achieve an immortal life, to escape death which had claimed so many around him.
By the time his machinations were discovered and he was driven out of the village, he could no longer feel any form of affection or remorse and by the time he had managed to resurrect his student, he could barely remember his reasons for it.
—
Nana did not remember where she came from. She simply woke up one day in a dark lab.
Being an experimental reanimation, Nana looked just like any other girl her age–aside from the perpetually vacant expression on her face.
In addition to having a hard time showing her emotions, she also had a terrible memory. For this reason, Orochimaru-sama usually had one of his summons accompany her.
Byakujutsu was a white snake with slitted amber eyes who liked to curl around her small shoulders and function as a reminder for all the things she failed to write down in the notebook she carried everywhere with her.
Orochimaru-sama and Byakujutsu were the only people she could always remember. Sometimes other followers of the snake Sannin got angry at her for forgetting them but there was simply nothing Nana could do about that. Besides, if they were important enough, Byakujutsu would remind her of them.
This was the case right now as Nana was faced with a scowling thirteen-year-old.
"I'm sorry, who are you again?"
The boy glared down at her, "You know exactly who I am."
Nana looked at her snake companion who stayed silent. "You must not be very important if Byakujutsu doesn't remember you either."
"Now, now," Orochimaru-sama's voice came from behind her when the boy's scowl deepened, "You must not take Nana-chan's words to heart, Sasuke-kun. She simply has a bad memory."
Sasuke scoffed, "Why is she here anyway? Seems pretty useless to me."
"Nana-chan is a better shinobi than you are," the Sannin remarked, "it is unlikely that you will ever be better than her but you can try, of course."
He then turned to the girl, "Nana-chan, have you checked on Kimimaro-kun as I asked you to?"
"Um," Nana looked at Byakujutsu, who nodded, "Yes, I have," she pulled out her notebook to show to him.
Orochimaru-sama took the offered notebook to read her report, "Very well, you may conduct your evening stretches."
Nana nodded and flitted off to her room.
—
The next morning Nana checked her diary to see if Orochimaru-sama had given her any instructions for the day. Not finding any, she proceeded to the training ground.
A boy was waiting there, around thirteen years old and short–only one head taller than her. He was also scowling at her.
"I'm Sasuke," he said when she was within earshot, "I want you to fight me."
Nana nodded, "Okay, I don't mind," and proceeded to wipe the floor with him.
Sasuke wheezed from where he had collapsed on the floor, defeated by what looked like an eight-year-old.
"How did you become that strong? Tell me!" he demanded.
"I'm sorry, I don't remember."
"What?"
"I cannot remember anything about my past. All I know is that I am a corpse and I do what I am ordered."
Sasuke squinted up at her, "You just follow Orochimaru's orders blindly then?"
"No, Nana gives Nana orders. Orochimaru-sama only gives instructions."
"Can you teach me then? How to fight like that?"
Nana looked at the boy, "I don't know how to teach but you can watch me to learn."
Sasuke got up, "When can we start?"
"If you want Nana's help, it is only fair if you help me first."
He crossed his arms over his chest, "What do you want?"
"... I don't remember."
—
"And where are you two going?" Kabuto asked the two small figures that were trying to leave the hideout.
"Sasuke-kun is helping Nana-chan out with an errand," Byakujutsu informed him when Nana blanked on the answer.
Kabuto huffed and went along his way.
"He must not be very important," Nana concluded, "I can't remember who he is."
"Not important at all," Sasuke agreed.
The two of them headed out of the lab and started combing the surrounding forest to see if they could find what Nana wanted.
"Oh," Nana suddenly said, catching Sasuke's attention.
"What is it? Do you remember?"
"No, but look," she pointed up at a tree, "a little finch. How cute."
Sasuke looked at it in doubt, "Is that what you wanted, maybe?"
Nana hummed, "No, but I would like one as a pet sometime. I think Byakujutsu would eat it, though. That would be sad."
"It would be tasty," Byakujutsu bobbed his head up and down.
Sasuke gave an annoyed huff and continued walking, "Let's keep looking then."
They eventually entered one of the few civilian towns in Oto no Kuni. The first place they looked was a flea market.
"Is this what you're looking for?" Sasuke picked up a wooden doll for her to look at.
"No."
"How about this?" it was a golden lucky cat.
"No."
A vase with blue flowers inked on it.
"No."
An old shogi game.
"No."
A tea set.
"No."
A child-sized kimono.
"No."
Sasuke pinched the bridge of his nose in annoyance, "If you could just tell me what you want, this would be so much easier."
"I'm sorry."
The boy sighed, "Let's head to a grocery store or something."
They made their way towards what seemed like the little town's only grocery store. As Sasuke led them through it, Nana suddenly stopped in front of one of the shelves.
"Oh, there it is."
Sasuke looked at the display, "You wanted coconut milk?"
Nana nodded, "I don't know what it tastes like… but I like it."
She took a couple of cartons out of the shelf before staring at Sasuke with big expressionless eyes.
The boy sighed and herded her to the cashier so he could pay for the coconut milk.
"It's so nice to see young boys take care of their little sisters," the cashier, an old woman with her hair in a tight knot on top of her head, said.
"Hn," was Sasuke's only response as he handed her the money.
"Have a nice day!" she called as they left–Nana waved at her.
When they left, the weather outside had turned for the worse, a harsh wind combing through the streets.
Nana reached for Sasuke's hand with her free one–the other one was holding the bag full of coconut milk.
"So I don't fly away," she explained.
Sasuke didn't seem too happy about it but let her hold his hand anyway.
—
Sasuke spent three years learning from both Orochimaru and the little dead girl he kept around for some reason. Though Sasuke would never admit it, a part of him had grown fond of her. She was less annoying than the other girls he knew, anyway.
Her constant forgetfulness had been an annoyance only for about a year. Somehow she had started remembering him afterwards, even if she could never recall their conversations.
Maybe Sasuke would even feel bad for her when he killed Orochimaru in front of the little girl, but he doubted that.
To Nana's luck, she was not in the room when Sasuke killed the Sannin–she had likely gone out to fetch medicine for him–and so when he looked down at the torn-apart snakes on the ground he could only wonder about how easy it had been.
"So that's it?"
But Orochimaru was not done yet.
Sasuke found himself in some sort of fleshy dreamscape, surrounded by all the previous faces that Orochimaru had worn underneath a thin layer of false skin.
"Those eyes will soon be mine!" Orochimaru laughed as a sort of tug-of-war of life forces began between the two.
One of them would absorb the other and only their individual strength could decide the victor.
But Sasuke hadn't taken his training lightly. He let the corrosive chakra of his curse mark consume its creator, burning the unshapely form of the Sannin.
"Impossible! I am the immortal Orochimaru! You can't!"
But Sasuke could.
He started absorbing the snake Sannin inside him. As he was almost done, it seemed like less and less of Orochimaru's will remained. But Sasuke could hear him mutter something.
"What is it?" he asked in a tone of bored curiosity.
"Nana-chan. You'll take care of Nana-chan, won't you?"
Sasuke looked down at the man who was almost completely gone and only when the Sannin was no more, he quietly said: "I promise."
—
Nana wasn't sure what to think of these new circumstances.
She had known, of course, that Orochimaru-sama didn't care for her as much as he pretended to but he had offered a form of safety to the girl.
With her forgetfulness, others often tried to take advantage of her but with Orochimaru-sama no one could ever succeed.
With him gone, she didn't quite know what to do.
"You interested in being a babysitter or something?" a voice asked.
Nana turned to see Sasuke come towards her with a white-haired boy following him. She thought he might have grown since the first time she met him (her notes just read "short, angry") but she couldn't be sure about it.
Sasuke ignored the comment from the boy and instead looked down at her. "I killed Orochimaru. He asked me to take you with me. Will you join my team?"
Nana mustered the boy.
"Okay."
"What, just like that?" the white-haired boy raised a brow.
"This is Suigetsu," Sasuke told her, ignoring his comments once more, "You don't have to remember his face."
"I won't."
"Hey! What's that supposed to mean?!"
The two ignored him as they made their way out of the hideout. Sasuke still had two more people to recruit.
"Guys? Come on!" Suigetsu called when he realized he was being ignored. "I hate you guys."